Pozen files to block generic migraine drug

Pozen has filed a motion to block Par Pharmaceutical from launching a generic version of the migraine drug Treximet (sumatriptan and naproxen sodium), which is marketed in the US by GlaxoSmithKline (GSK).

Two of Pozen's three US patents on the drug are set to expire in August 2017, while the third runs through October 2025. However, the patents have been challenged by several generic companies, including Par. As the first company to file an abbreviated new drug application (ANDA) containing a patent challenge, Par would have 180 days of exclusivity for its generic product on the US market.

Par submitted its ANDA in October 2008, just months after the Food and Drug Administration (FDA) had approved the branded version of the drug. The company hopes to launch its generic version in April of this year, when regulatory exclusivity for Treximet expires.

Pozen said it has filed a motion for a preliminary injunction in the US District Court for the Eastern District of Texas seeking to prevent Par from launching a generic version of Treximet. Pozen has patent litigation over the drug ongoing against Par, Alphapharm, Teva Pharmaceuticals and Dr Reddy's Laboratories in the Texas court, where the cases were consolidated into a single suit. The company reached a settlement with Teva in April 2010 and expects a decision in the case against the other three companies shortly.

Treximet was approved by the FDA in April 2008 for the acute treatment of migraine attacks, with or without aura, in adults. GSK sells the drug in the US and pays Pozen an 18 per cent royalty based on net sales.

The partnership began in 2003, when GSK signed an agreement with Pozen for the development and commercialisation of the migraine drug.